Dual 2.5GHz Power Mac G5

Ars Technica takes Apple's top of the line Dual 2.5GHz Power Mac G5 out for a …

Benchmarks

Benchmarking is always difficult, especially when trying to make comparisons across platforms. Pure benchmarking apps have their limitations, primarily because they don't always simulate "real world" usage. However, they can provide a useful point of comparison, especially within a single platform. For the G5, we used the venerable Xbench 1.1.3 as well as Cinebench 2003.

We also wanted to try some application benchmarks. For those, we used a series of hand-timed Photoshop filters on a 45.7MB file using Photoshop CS, delved into iMovie to export a 1.1GB, 5:25 iMovie project to QuickTime, then another video test exporting a 1.08GB QuickTime file to a 320x240 mpeg-4, and finally a Unreal Tournament 2004 Demo benchmark. We would loved to have tested out Doom 3 on this baby, but it's sadly not yet available for OS X.

Mac comparison systems were a "Sawtooth" G4 tower with an NVIDIA GeForce4 MX(400MHz), a Dual 800MHz "Quicksilver" G4 tower with a GeForce4 Titanium (4600), a Dual 1.25GHz "Mirrored Drive Doors" tower with an ATI Radeon 9000 Pro, and a Dual 2.0GHz Rev. B G5 tower with also with the ATI Radeon 9800XT. All tests were run with the machines configured with 1GB of RAM. The machines were rebooted between each suite of tests. Unfortunately, not all test systems were available for each test.

First off is the standard for Apple reviews, the Photoshop bakeoff. It's an old standard for Steve Jobs to show off the performance of Macs vs. Windows when he rolls out new towers. As noted above, the tests were hand-timed.

Ye olde Photoshop bake-off, part the first

Ye olde Photoshop bake-off, part the second

From the benchmarks, it's evident that the G5 blows the doors off of the older Power Macs. To be fair, the 400MHz machine is nearly five years old at this point.

Playing with iMoive and QuickTime

The G5 is a huge asset in working with video as well. Note the strong performance of the dual processor machines compared to the single-CPU G4.

UT2K4 demo pitting the G4s against the G5 at 800x600

The G5 tested at higher resolutions

With the G4 400, I actually made a test run of the benchmarks with the original Rage 128 Pro card. It was not a pretty sight. As you can see from the results, the G5 easily bested the older machines. The combination of a faster CPU, more bandwidth, and a better video card makes a lot of difference. It even looks as though the Dual 2.5GHz G5 would make a pretty decent gaming machine, although not as good as a PC. I'm curious to see how much the 8X NVIDIA 6800 Ultra will do to improve gaming and video subsystem performance.

And it's a shame Doom 3 isn't yet out on OS X.

Cinebench 2003 on a Dual 1.25GHz G4 and the review system

The G5 performed quite well compared to the Dual 1.25GHz G4. The higher scores are a function of the faster RAM as well as the CPU. If you want to put these scores into a Battlefront context, check out the Cinebench 2003 thread. Note that the G5 used the G5-optimized beta version of Cinebench 2003.

Xbench, part 1

Xbench, part 2

Xbench is the best-known Macintosh benchmarking application. It runs a series of over 30 tests that are grouped into the seven categories seen above. Unfortunately, it was the only benchmark for which we had all five comparison systems available.

Predictably, the Dual 2.5GHz outperformed all of the other machines, with the sole exception of the disk test. There, it was bested by the Dual 2.0GHz (Rev. B) machine. The 400 has an ATA/33 controller and Dual 800MHz sports an Ultra ATA/66 controllers while the Dual 1.25GHz has an Ultra ATA/100 controller. Both G5s used 7200rpm SATA drives.

Where the two G5s really shone was in the memory test and user interface tests. With the memory test, the benefit of the dual-channel RAM and fast DDR pipe to the CPU are readily apparent. While the Dual 1.25GHz G4 has DDR RAM, the bus between the northbridge and CPU is single-pumped. The user interface tests highlight both the increased system bandwidth and the leaps ahead in video cards in the past year or so.

In comparing the performance of the two G5s, the Dual 2.5GHz has a decided edge over the Dual 2.0GHz G5 in nearly every test. The 2.5 CPUs are 25% faster than the 2.0's, and the scores on most of the benchmarks reflect that difference.